smiley and d



O. SMILEY AND D. A. ANDERSON.

Patented Dec. 28, 1920.

INVENTORS ATTORNEY PATENT OFFICE.

ORVALL SMILEY AND DON AYRES ANDERSON, OF INDIANAPOLIS, INDIANA.

AMPLIFIER FOR STETHOSCOPES.

Specification of Letters Patent.

Patented Dec. 28, 1920.

Application filed May 26, 1919. Serial No. 299,744.

To all whom it may concern:

Be it known that we, ORVALL SMiLnY and Don Areas ANDERSON, citizens of the United States of America, and residents of Indianapolis, in the county of Marion and State of Indiana, have invented certain new and useful Improvements in Amplifiers for Stethoscopes, of which the following is a specification.

This invention relates to improvements in amplifiers for Stethoscopes especially for that class employed for ascertaining the location of abnormal working conditions in mechanical devices particularly automobile engines. The present invention is applicable to instruments of the character of that shown in our previous application for stethoscopes for motors, Sr. No. 289,770, filed April 12, 1919.

The object of the present invention is to afford a device having the effect of concentrating in a sound chamber the vibrations imparted thereto by the diaphragm of the instrument, so that the operator will be en abled to detect with greater certainty noises that animate the diaphragm. And another object is to provide means within the sound chamber of a stetho phone that tends to render inaudible reactionary sounds therein.

The objects of the invention are accomplished by the construction illustrated in the accompanying drawings in which Figure 1 is an end view of the receiver of a stetho phone with the diaphragm thereof partially cut away and exposing the drum within its sound chamber, the drum being shown partly cut away and in section;

Fig. 2 is an elevation of Fig. 1 shown also partially cut away and in section; and

Fig. 3 is an external view of the drum.

Similar characters of reference indicate corresponding parts throughout the several views and referring now to the same:

1 is a metallic bell having therein a sound chamber 2 and at its apex a Y-tube 3 which has open communication with the chamber. The bell has fixed in its large end a diaphragm 4. and also a mufile-ring 5 projects from the same end of the bell.

A closed drum or capsule 6 having a round flat base 7 and a rounded opposite end 8 is secured to the inner face of the diaphragm 4: in concentric relation therewith, the base 7 of the capsule being secured to the dia phragm by means of glue or by any other suitable expedient. The drum is constructed with walls of extreme thinness and of light stilt material such as wood and is light in weight, it being the intention that the drum shall move readily with the diaphragm in its vibrations. The Y-tube 3 has flexible tubes 9, attached to its branches, which are intended for connection with a head-piece (not shown) of the usual type for connection to the operators cars.

In the operation of the invention, the re ceiver is applied to the motor or other mechanical object by pressing the open end of the muffle-ring flatly against its body and then observing the sounds as they effect the diaphragm and drum. This operation is re peated upon various parts of the machine so as to locate the source of objectionable sounds. As the diaphragm becomes affected with vibrations by the sounds, the drum is vibrated directly because of its contact with the diaphragm and is also sympathetically aifected with vibrations which set up within its hollow chamber 10 as a result of the close relation of its base with the vibrating diaphragm 4;. Thus, the vibrations in the chamber 2 of the bell occasioned by the action of the diaphragm are enhanced by the sympathetic vibrations of the drum, and in this manner the sounds affecting the instrument are rendered more perfectly distinct and detectable.

What we claim is 1. In an amplifier for a stethoscope having a receiving bell. and diaphragm fixed therein, a hollow wooden drum having a flat base and a closed chamber therein, said drum extending within the chamber of the bell with its base in secured relation with the diaphragm.

2. In an amplifier for a stethoscope hav ing a receiving chamber and diaphragm, a thin walled capsule having a chamber there in and extending into the receiving chamber, one end of the capsule being fixed to the inner face of the diaphragm and being adapted to vibrate therewlth.

3. In an amplifier for a stethoscope having a vibratory diaphragm and receiving chamber a drum having a closed chamber therein, one end of the drum being secured flatly against the diaphragm so that vibrations of the latter will cause sympathetic vibrations to set up Within the chamber 01 the drum.

In testimony whereof We a'ffix our signatures, in presence of two Witnesses.

ORVALL SMILEY. DON AYRES ANDERSON.

Vitnesses C. L. BITTER. HARRY B. DYNES. 

